Which virus category is known for corrupting the file system by manipulating the FAT structure?

• A. Web scripting virus
• B. Shell virus
• C. FAT virus
• D. Logic bomb

Answer: (C)

Manipulating the file system’s mapping structure to corrupt files is what FAT viruses do. They target the File Allocation Table, the data structure that tracks how disk clusters are linked to form files. By changing FAT entries, the virus can mislink clusters, create orphaned or overlapping data, or point to invalid locations. This directly corrupts the file system and can lead to missing, damaged, or unreadable files and broader system instability.

Other types don’t focus on the disk’s allocation map: a web scripting virus operates through malicious code embedded in web content, a shell virus targets the command interpreter or shell scripts, and a logic bomb is malicious code that waits for a trigger. None are inherently about corrupting the file system by altering the FAT structure. Therefore, the FAT virus is the category that matches this behavior.